Vaporizing device



Jan. 14, 1969 Sheet Filed Oct. 23. 1965 R H .Hu I! HM mr N mw m m J m h, wan? kw? -lll a 2 J J 2 2 J V J J J a FIGZ Jan. 14, 1969 c, wlTTWER I 3,421,841

VAPORIZING DEVICE Filed on. 23. 1965 Sheet 2 of 2 I'NVENTOR. J00 C. WITTWER United States Patent 8 Claims This application relates to a vaporizing system, and more particularly relates,to such a system for mothproofing and similar purposes. A specific embodiment of this invention relates to the emission of insecticides which are formed as solid nuggets which may be vaporized.

The vapors emitted in a mothproofing device have heretofore depended only upon the natural rate of evaporation of the mothproofing crystal, as well as the variations in temperature, humidity, and the like. While many gas controlled systems exist in commercial applications, such are not entirely satisfactory for use in an ordinary closet of a home owner. Thus, in order to increase the effectiveness of any vaporizing unit, such as mothproofing and mildewproofing to name two, the home owner (or apartment dweller) must either increase the number of mothproofing units or rely upon chance that the temperature and humidity are at a level to accommodate a suflicient rate of crystal evaporation.

In a related aspect of this invention, I have provided a system for insect control. It is known to employ a number of insecticide strips which are located in a large room, or barns, food plants, and the like. Such strips are formed as insecticide impregnated resin. One type of such strip is currently sold as a Vapona insecticide strip. Such strips are essentially solid and depend upon vaporization of the insecticide compounds for their operation. However, when employed in a barn or other area which does not have suitable temperature control, the effectiveness of such strips decreases.

An object of my invention is to provide a small, safe, compact evaporating system for closet mothproofing and the like.

A further object of this invention is to provide a small but effective heat control system for vaporizing solid substances.

Another object of this invention is to provide a portable vaporizing system for insecticide control. Still another object of this invention is to provide an effective vaporizing system which prevents mildew.

Still another object of this invention is to provide a small, inexpensive mothproofing unit.

Other objects and features of this invention will become apparent from a reading of the following specifications taken in connection with the following drawings.

FIG. 1 is a diagram showing my vaporizing unit installed in a closet.

FIG. 2 is a more detailed, enlarged, perspective view of the active elements of my unit.

FIGS. 3a-e are cross-section, diagrammatic views of various embodiments of the active element.

FIG. 4 is a block diagram showing an automatic system for regulating the vaporization rate.

FIG. 5 is a sectional view along the lines 5-5 of FIG. 3d showing the various positions of the crystals in this embodiment.

FIG. 6 is a diagram of an insecticide control. Referring now to FIG. 1, there is shown a conventional closet 10 and door 11. Along one of the interior walls 12 of the closet there is installed a vaporization control unit 20 which may be simply mounted on a bracket 21 hook or other suspending means. Preferably the unit is mounted horizontally, suspended slightly from the ceiling to allow the emitted vapor to fall more or less with wide distribu- 3,421,841 Patented Jan. 14, 1969 tion. Within the vapor control unit 20, there are active vapor emitting elements, collectively designated 22, which respond to the heat generated by electrical current from a conventional source. As shown in FIG. 1, the current source 24 is a house wall socket; however, a battery or other portable electrical source is contemplated with this invention.

The active vaporization elements comprise an outer, substantially chemically inert, heat resistant plastic, tubular means 26 (FIG. 2) having a plurality of repeating, closely spaced openings 27 in which are positioned small, conventional mothproofing crystals 30 or flakes. The dimensions of the crystals are, of course, greater than the size of openings 27. The tubular structure is formed as a mesh and it will be apparent that openings 27 allow easy egress of the crystal vapor. The outer tubular means 26 is closed by end caps 32 and 34.

Positioned within the outer tube 26 and supported by suspension means 36, such as a wire or pin, heat welded or glued, is a heating element 38 comprising a second tubular means 40 having openings in the outer surface. As so disclosed, the mesh of tubular means 40 is similar to the mesh of outer tubular means 26. The heat source 42 is mounted within the tubular means 40. Various embodiments of the heating element 38 are shown and described in my prior Patent No. 3,163,842 to which further reference may be made.

The heat source 42 comprises flexible tape-like strips, one form of which is sold under the trademark Cellotherm. This heat-strip is essentially a sandwich of a conductive coating and copper electrodes between two sheets of asbestos. The electrodes run along the edges and the entire area between the electrodes emits uniform heat. The element is in roll form and may be cut to any length without changing the watt density. Another sample of a tapelike flexible heating element comprises woven fibrous glass tape having conductive silicone rubber in the interstices and electrical conductors along the longitudinal edges.

The flexible heating element shown in the drawings in preferred.

When electrical current is sent from the lead-in wires to the heat source 42, the heated air within tubular means 38 passes through the openings 40 thereof so as to contact crystals 30. The crystals vaporize quicker upon being heated and emit their vapors through the opening 27 of the outer tubular means.

The length of time that the electrical energy will be on may be controlled by a simple time control switch or relay which turns the current on for a predetermined period of time one or more times per day. The time control can be manually operated also by a simple switch 51. Alternately, an on-ofi control can be actuated by a switch response to the opening and closing of a door.

If desired, as shown in FIG. 4, the system may be operated automatically in accordance with a conventional temperature sensing element such as a thermocouple which turns on and off the control switch 50' which controls the current flow. Or a humidistat can be used to sense variations in humidity and thus control current flow.

Gas sensing means may be used to control current flow. It will be apparent that the surface of the heating element, and its relative position within its housing, as well as the overall tubular housing, will vary depending upon particular requirements; and as a result I have shown a plurality of different enclosure structures in FIGS. 3a, 4. In all of these embodiments, the numeral 26' is applied to an outer tubular means as described previously in connection with the tubular means 26 of FIG. 2.

In FIG. 3a the heat source element 42a is surrounded by a first tubular mesh 62 constituting a base and a pair of walls extending sidewalls '63, 64 to define a flue 65. Each of these walls has openings, like a mesh, so as to 3 allow the heat to pass through. The heat is then applied to the crystals 30 outside of the flue and in the tubular means 26'.

In FIG. 3b the flue has been omitted and the heat source element 42b is fixedly positioned in a very small arcuate shape.

In FIGS. 3c and 3d the heat source elements 42c and 42d have a more substantial curvature and are surrounded by a tubular separator. The separator is also of the plastic, heat insulative type having a plurality of openings.

In FIG. 30 the heating element lies adjacent to the Wall of the inner tubular structure, while in FIG. 3d the heating element 42d lies adjacent to the outer wall. The diagram of FIG. 3e illustrates a heat source element 42e within a tubular separator 70 having a barrier element 73 which is similar to the structure described in my previous patent.

FIG. 5 is an enlarged sectional view along 5-5 of FIG. 3d and is intended to show one form of heating elemeat 42 in conjunction with the crystals 30.

In one form of the invention, the outer tubular structure 40 consists of Vexar housing field and the crystals 30 are paradiphenyl crystals for mildewproofing or paradichlorbenzene for mothproofing. Other types of crystals or nuggets include solids impregnated in cloth or plastic strips or impregnated in clay, porcelain discs and the like.

In the embodiment of FIG. 6, the solid material is formed as the insecticide impregnated resin strips. Such strips are located within the tubular plastic means 2-6. In this embodiment, the plastic strips are maintained at a substantially constant and effective operating temperature as a result of the heat which is emitted from the heating element. Each of these tubular means may be hung or otherwise positioned at predetermined spaces in a barn and under all of these circumstances the vaporization rate and amount can be more accurately controlled independent of the outside environment.

I claim:

1. A vaporizing device for increasing the rate of vaporization of moth repellant crystals comprising an outer tubular housing of heat resistant plastic having a plurality of openings in the walls thereof, an inner tubular housing within said outer tubular housing and constructed of heat resistant plastic having a plurality of openings in the walls thereof, moth repellent crystals in said outer tubular housing positioned between it and said inner tubular housing, flexible electrically responsive heat emitting means within said inner tubular housing, means for coupling said heat emitting means to a source of electrical energy, and electrical means coupled to said flexible heat emitting means for controlling the flow of electrical energy thereto.

2. A vaporizing device for increasing the rate of vaporization of solid substances comprising an outer tubular housing constructed of a heat resistant and electrically nonconductive material having a plurality of relatively closely spaced openings therein, flexible electrically responsive heat emitting means within said housing, means for coupling said heat emitting means to a source of electrical energy, vapor emitting crystals positioned within said housing, electrically nonconductive means separating said heat emitting means from said vapor emitting crystals and having heat flow passages therein, and means for controlling the duration of electrical current to said heat emitting means.

3. A vaporizing device for increasing the rate of vaporization of moth repellant nuggets comprising an outer tubular housing of heat resistant plastic having a plurality of openings in the walls thereof, an inner tubular housing within said outer tubular housing and constructed of heat resistant plastic having a plurality of openings in the wall thereof, moth repellant crystals in said outer tubular housing positioned between it and said inner tubular housing, flexible electrically responsive heat emitting means within said inner tubular housing, means for coupling said heat emitting means to a source of electrical energy, sensing means to determine a selected environmental characteristic located in relatively close proximity to said device, and electrical means responsive to said sensing means coupled to said flexible heat emitting means for controlling the flow of electrical current thereto.

4. The device of claim 3 in which said environmental characteristic is temperature and said sensing means and electrical means include a thermostatically controlled switch.

5. A vaporizing device for increasing the rate of vaporization of solid substances comprising an outer housing having a plurality of relatively closely spaced openings therein, crystal vapor emitting means positioned within said housing, flexible heating means responsive to electrical current within said housing, means for coupling said heat emitting means to a source of electrical energy, and tubular separating means surrounding said flexible heating means and electrically insulating said heating means from said vapor emitting means; said separating means constructed of an open mesh heat resistant and electrically nonconductive plastic.

6. The vaporizing device of claim 5 in which said vapor emitting means comprises nuggets of paradiphenyl.

7. The vaporizing device of claim 5 in which said vapor emitting means comprises nuggets of paradichlorobenzene.

8. The vaporizing device of claim 5 in which said vapor emitting means comprises a porous substance which has been impregnated with solid vapor forming insecticides.

References Cited UNITED STATES PATENTS 1,913,571 6/1933 Strongsen 21-119 2,513,919 7/ 1950 Costello 21-119 XR 2,541,637 2/1951 Christopher et al. 21-119 XR 2,660,828 12/1953 Abrams 21-119 XR 2,737,572 3/1956 Ernst 21-119 XR 2,742,342 4/1956 Dew et al 21-119 XR 2,758,412 8/1956 Loibl 21-119 XR 3,290,112 12/ 1966 Gillenwater et al. 21-110 FOREIGN PATENTS 542,572 6/ 1957 Canada.

MORRIS O. WOLK, Primary Examiner.

B. S. RICHMAN, Assistant Examiner.

US. Cl. X.R. 21-122; 43-129 

5. A VAPORIZING DEVICE FOR INCREASING THE RATE OF VAPORIZATION OF SOLID SUBSTANCES COMPRISING AN OUTER HOUSING HAVING A PLURALITY OF RELATIVELY CLOSELY SPACED OPENINGS THEREIN, CRYSTAL VAPOR EMITTING MEANS POSITIONED WITHIN SAID HOUSING, FLEXIBLE HEATING MEANS REPONSIVE TO ELECTRICAL CURRENT WITHIN SAID HOUSING, MEANS FOR CONPLING SAID HEAT EMITTING MEANS TO A SOURCE OF ELECTRICAL ENERGY, AND TUBULAR SEPARATING MEANS SURROUNDING SAID FLEXIBLE HEATING MEANS AND ELECTRICALLY INSULATING SAID HEATING MEANS FROM SAID VAPOR EMITTING MEANS; SAID SEPARATING MEANS CONSTRUCTED OF AN OPEN MESH HEAT RESISTANT AND ELECTRICALLY NONCONDUCTIVE PLASTIC. 